AngularJS: one-time binding syntax

Prettier 1.15.2 Playground link

--parser angular

Input:

<p>
  {{ ::vm.user }}
</p>

Output:

SyntaxError: Unexpected token :
    at o (https://prettier.io/lib/parser-angular.js:1:43175)
    at t.parseNgInterpolation (https://prettier.io/lib/parser-angular.js:1:44299)
    at n (https://prettier.io/lib/parser-angular.js:1:54796)
    at Object.t.parseInterpolation (https://prettier.io/lib/parser-angular.js:1:55134)
    at https://prettier.io/lib/parser-angular.js:1:55771
    at Object.parse (https://prettier.io/lib/parser-angular.js:1:55427)
    at Object.parse$2 [as parse] (https://prettier.io/lib/standalone.js:12931:19)
    at textToDoc (https://prettier.io/lib/standalone.js:15724:23)
    at https://prettier.io/lib/standalone.js:15712:14
    at Object.embed$2 [as embed] (https://prettier.io/lib/standalone.js:20444:55)

Expected behavior:

No error.

Notice that AngularJS and Angular aren’t the same framework. The one with JS is an older incompatible version. However, their expression syntaxes seem to be mostly compatible except for this one-time binding thing. Docs: https://docs.angularjs.org/guide/expression#one-time-binding

[ikatyang]

Note that syntax errors won’t be produced in child languages, this is a bug in our playground. Unknown syntax will be preserved if you’re using CLI.

Supporting a new syntax isn’t that simple, we need a parser for it (something like angular-estree-parser but for angular.js) since we don’t know what’s the difference between them, they look the same but we’re not sure, especially for edge cases.

And also I’m not sure if we should support angular.js, is it still developing not maintenance-only?

[thorn0]

@icopp The syntax for filters/pipes is the same in AngularJS and Angular. Please prove me wrong if I am.

UPD yep, I was wrong, see #5586